Compositions and methods for combination antiviral therapy

ABSTRACT

The present invention relates to therapeutic combinations of [9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine (GS-7340) and (2R,5S, cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-( 1 H)-pyrimidin-2-one (emtricitabine, (−)-cis FTC, Emtriva™) and their physiologically functional derivatives. The combinations may be useful in the treatment of HIV infections, including infections with HIV mutants bearing resistance to nucleoside and/or non-nucleoside inhibitors. The present invention is also concerned with pharmaceutical compositions and formulations of said combinations of GS-7340 and emtricitabine, and their physiologically functional derivatives, as well as therapeutic methods of use of those compositions and formulations.

[0001] This non-provisional application claims the benefit ofProvisional Application Nos. 60/440,308 and 60/440,246, both filed Jan.14, 2003, which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The invention relates generally to combinations of compounds withantiviral activity and more specifically with anti-HIV properties. Inparticular, it relates to chemically stable combinations of structurallydiverse anti-viral agents.

BACKGROUND OF THE INVENTION

[0003] Human immunodeficiency virus (HIV) infection and related diseasesare a major public health problem worldwide. Human immunodeficiencyvirus type 1 (HIV-1) encodes at least three enzymes which are requiredfor viral replication: reverse transcriptase (RT), protease (Prt), andintegrase (Int). Although drugs targeting reverse transcriptase andprotease are in wide use and have shown effectiveness, particularly whenemployed in combination, toxicity and development of resistant strainshave limited their usefulness (Palella, et al N. Engl. J. Med. (1998)338:853-860; Richman, D. D. Nature (2001) 410:995-1001). Humanimmunodeficiency virus type 1 (HIV-1) protease (Prt) is essential forviral replication and is an effective target for approved antiviraldrugs. The HIV Prt cleaves the viral Gag and Gag-Pol polyproteins toproduce viral structural proteins (p17, p24, p7 and p6) and the threeviral enzymes. Combination therapy with RT inhibitors has proven to behighly effective in suppressing viral replication to unquantifiablelevels for a sustained period of time. Also, combination therapy with RTand Prt inhibitors (PI) have shown synergistic effects in suppressingHIV replication. Unfortunately, a high percentage, typically 30 to 50%of patients currently fail combination therapy due to the development ofdrug resistance, non-compliance with complicated dosing regimens,pharmacokinetic interactions, toxicity, and lack of potency. Therefore,there is a need for new HIV-1 inhibitors that are active against mutantHIV strains, have distinct resistance profiles, fewer side effects, lesscomplicated dosing schedules, and are orally active. In particular,there is a need for a less onerous dosage regimen, such as once per dayoral dosing, optimally with as few pills as possible.

[0004] The use of combinations of compounds can yield an equivalentantiviral effect with reduced toxicity, or an increase in drug efficacy.Lower overall drug doses can reduce the frequency of occurrence ofdrug-resistant variants of HIV. Many different methods have been used toexamine the effects of combinations of compounds acting together indifferent assay systems (Furman WO 02/068058). Lower doses predictbetter patient compliance when pill burden decreases, dosing schedulesare simplified and, optionally if synergy between compounds occurs(Loveday, C. “Nucleoside reverse transcriptase inhibitor resistance”(2001) JAIDS Journal of Acquired Immune Deficiency Syndromes26:S1O—S24). AZT (zidovudine™, 3′-azido, 3′-deoxythymidine) demonstratessynergistic antiviral activity in vitro in combination with agents thatact at HIV-1 replicative steps other than reverse transcription,including recombinant soluble CD4 castanospermine and recombinantinterferon-α. However, it must be noted that combinations of compoundscan give rise to increased cytotoxicity. For example, AZT andrecombinant interferon-α have an increased cytotoxic effect on normalhuman bone marrow progenitor cells.

[0005] Chemical stability of combinations of antiviral agents is animportant aspect of co-formulation success and the present inventionprovides examples of such combinations.

[0006] There is a need for new combinations of orally-active drugs forthe treatment of patients infected with certain viruses, e.g. HIV, thatprovide enhanced therapeutic safety and efficacy, impart lowerresistance, and predict higher patient compliance.

SUMMARY OF THE INVENTION

[0007] The present invention provides combinations of antiviralcompounds, in particular compositions and methods for inhibition of HIV.In an exemplary aspect, the invention includes a combination of GS-7340and emtricitabine which has anti-HIV activity. The combination ofGS-7340 and emtricitabine is both chemically stable and eithersynergistic and/or reduces the side effects of one or both of GS-7340and emtricitabine. Increased patient compliance is likely in view of thelower pill burden and simplified dosing schedule.

[0008] The present invention relates to therapeutic combinations of9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) and (2R, 5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine), and their use in the treatment of HIV infectionsincluding infections with HIV mutants bearing resistance to nucleosideand/or non-nucleoside inhibitors. The present invention is alsoconcerned with pharmaceutical compositions and formulations of saidcombinations of GS-7340 and emtricitabine. Another aspect of theinvention is a pharmaceutical formulation comprising a physiologicallyfunctional derivative of GS-7340 or a physiologically functionalderivative of emtricitabine, including FTC and 3TC.

[0009] FTC is4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-oneand includes all diastereomers, enantiomers, and mixtures thereof, inany proportion. For example, FTC includes the single enantiomeremtricitabine.

[0010] Therapeutic combinations and pharmaceutical compositions andformulations of the invention include the combination of phosphonamidatePMEA or PMPA compounds with FTC or(2R,5S,cis)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(3TC, Lamivudine, Epivir™), and their use in the treatment of HIVinfections.

[0011] One aspect of the invention is a method for the treatment orprevention of the symptoms or effects of an HIV infection in an infectedanimal which comprises administering to, i.e. treating, said animal witha therapeutically effective amount of a formulation comprising9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) or a physiologically functional derivative thereof, and(2R,5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine) or a physiologically functional derivative thereof.

[0012] Another aspect of the invention is a unit dosage form of atherapeutic combination comprising GS-7340 and emtricitabine, orphysiological functional derivatives thereof. The unit dosage form maybe formulated for administration by oral or other routes and isunexpectedly chemically stable in view of the properties of thestructurally diverse components.

[0013] Another aspect of the invention is directed to a chemicallystable combination antiviral compositions comprising GS-7340 andemtricitabine. In a further aspect of the invention, the chemicallystable combinations of GS-7340 and emtricitabine further comprise athird antiviral agent. In this three-component mixture, the uniquechemical stability of GS-7340 and emtricitabine is taken advantage of inorder to enable the combination with the third antiviral agent.Particularly useful third agents include, by way of example and notlimitation, those of Table A. Preferably, the third component is anagent approved for antiviral use in humans, more preferably, it is anNNRTI or a protease inhibitor (PI), more preferably yet, it is an NNRTI.In a particularly preferred embodiment, the invention is directed to acombination of the chemically stable mixture of GS-7340 andemtricitabine together with efavirenz.

[0014] Another aspect of the invention is a patient pack comprising atleast one, typically two, and optionally, three active ingredientsselected from GS-7340, emtricitabine, and other antiviral agents, and aninformation insert containing directions on the use of GS-7340 andemtricitabine together in combination.

[0015] Another aspect of the invention is a process for preparing thecombinations hereinbefore described, which comprises bringing intoassociation GS-7340 and emtricitabine of the combination in a medicamentto provide an antiviral effect. In a further aspect of the presentinvention, there is provided the use of a combination of the presentinvention in the manufacture of a medicament for the treatment of any ofthe aforementioned viral infections or conditions.

DETAILED DESCRIPTION OF THE INVENTION

[0016] While the invention will be described in conjunction with theenumerated embodiments, it will be understood that they are not intendedto limit the invention to those embodiments. On the contrary, theinvention is intended to cover all alternatives, modifications, andequivalents, which may be included within the scope of the presentinvention as defined by the claims.

[0017] Definitions

[0018] Unless stated otherwise, the following terms and phrases as usedherein are intended to have the following meanings:

[0019] When tradenames are used herein, applicants intend toindependently include the tradename product and the activepharmaceutical ingredient(s) of the tradename product.

[0020] The term “chemical stability” means that the two primaryantiviral agents in combination are substantially stable to chemicaldegradation. Preferably, they are sufficiently stable in physicalcombination to permit commercially useful shelf life of the combinationproduct. Typically, “chemically stable” means that a first component ofthe mixture does not act to degrade a second component when the two arebrought into physical combination to form a pharmaceutical dosage form.More typically, “chemically stable” means that the acidity of a firstcomponent does not catalyzes or otherwise accelerate the aciddecomposition of a second component. By way of example and notlimitation, in one aspect of the invention, “chemically stable” meansthat GS-7340 is not substantially degraded by the acidity ofemtricitabine. “Substantially” in this context means at least about lessthan about 10%, preferably less than about 1%, more preferably less thanabout 0.1%, more preferably yet, less than about 0.01% acid degradationof GS-7340 over a 24-hour period when the products are in apharmaceutical dosage form.

[0021] The terms “synergy” and “synergistic” mean that the effectachieved with the compounds used together is greater than the sum of theeffects that results from using the compounds separately, i.e. greaterthan what would be predicted based on the two active ingredientsadministered separately. A synergistic effect may be attained when thecompounds are: (1) co-formulated and administered or deliveredsimultaneously in a combined formulation; (2) delivered by alternationor in parallel as separate formulations; or (3) by some other regimen.When delivered in alternation therapy, a synergistic effect may beattained when the compounds are administered or delivered sequentially,e.g. in separate tablets, pills or capsules, or by different injectionsin separate syringes. In general, during alternation therapy, aneffective dosage of each active ingredient is administered sequentially,i.e. serially, whereas in combination therapy, effective dosages of twoor more active ingredients are administered together. A synergisticanti-viral effect denotes an antiviral effect which is greater than thepredicted purely additive effects of the individual compounds of thecombination.

[0022] The term “physiologically functional derivative” means apharmaceutically active compound with equivalent or near equivalentphysiological functionality to GS-7340 or emtricitabine whenadministered in combination with another pharmaceutically activecompound in a combination of the invention. As used herein, the term“physiologically functional derivative” includes any physiologicallyacceptable salt, ether, ester, prodrug, solvate, stereoisomer includingenantiomer, diastereomer or stereoisomerically enriched or racemicmixture, and any other compound which upon administration to therecipient, is capable of providing (directly or indirectly) such acompound or an antivirally active metabolite or residue thereof.

[0023] “Bioavailability” is the degree to which the pharmaceuticallyactive agent becomes available to the target tissue after the agent'sintroduction into the body. Enhancement of the bioavailability of apharmaceutically active agent can provide a more efficient and effectivetreatment for patients because, for a given dose, more of thepharmaceutically active agent will be available at the targeted tissuesites.

[0024] The compounds of the combinations of the invention may bereferred to as “active ingredients” or “pharmaceutically active agents.”

[0025] The term “prodrug” as used herein refers to any compound thatwhen administered to a biological system generates the drug substance,i.e. active ingredient, as a result of spontaneous chemical reaction(s),enzyme catalyzed chemical reaction(s), and/or metabolic chemicalreaction(s).

[0026] “Prodrug moiety” means a labile functional group which separatesfrom the active inhibitory compound during metabolism, systemically,inside a cell, by hydrolysis, enzymatic cleavage, or by some otherprocess (Bundgaard, Hans, “Design and Application of Prodrugs” inTextbook of Drug Design and Development (1991), P. Krogsgaard-Larsen andH. Bundgaard, Eds. Harwood Academic Publishers, pp. 113-191). Prodrugmoieties can serve to enhance solubility, absorption and lipophilicityto optimize drug delivery, bioavailability and efficacy. A “prodrug” isthus a covalently modified analog of a therapeutically-active compound.

[0027] “Alkyl” means a saturated or unsaturated, branched,straight-chain, branched, or cyclic hydrocarbon radical derived by theremoval of one hydrogen atom from a single carbon atom of a parentalkane, alkene, or alkyne. Typical alkyl groups consist of 1-18saturated and/or unsaturated carbons, such as normal, secondary,tertiary or cyclic carbon atoms. Examples include, but are not limitedto: methyl, Me (—CH₃), ethyl, Et (—CH₂CH₃), acetylenic (—C≡CH),ethylene, vinyl (—CH═CH₂), 1-propyl, n-Pr, n-propyl (—CH₂CH₂CH₃),2-propyl, i-Pr, i-propyl (—CH(CH₃)₂), allyl (—CH₂CH═CH₂), propargyl(—CH₂C≡CH), cyclopropyl (—C₃H₅), 1-butyl, n-Bu, n-butyl (—CH₂CH₂CH₂CH₃),2-methyl-1-propyl, i-Bu, i-butyl (—CH₂CH(CH₃)₂), 2-butyl, s-Bu, s-butyl(—CH(CH₃)CH₂CH₃), 2-methyl-2-propyl, t-Bu, t-butyl (—C(CH₃)₃), 1-pentyl,n-pentyl, (—CH₂CH₂CH₂CH₂CH₃), 2-pentyl (—CH(CH₃)CH₂CH₂CH₃), 3-pentyl(—CH(CH₂CH₃)₂), 2-methyl-2-butyl (—C(CH₃)₂CH₂CH₃), cyclopentyl (—C₅H₉),3-methyl-2-butyl (—CH(CH₃)CH(CH₃)₂), 3-methyl-1-butyl (—CH₂CH₂CH(CH₃)₂),2-methyl-1-butyl (—CH₂CH(CH₃)CH₂CH₃), 1-hexyl (—CH₂CH₂CH₂CH₂CH₂CH₃),5-hexenyl (—CH₂ CH₂CH₂CH₂CH═CH₂) 1-hexyl (—CH(CH₃)CH₂CH₂CH₂CH₃), 3-hexyl(—CH(CH₂CH₃)(CH₂CH₂CH₃)), cyclohexyl (—C₆H₁₁), 2-methyl-2-pentyl(—C(CH₃)₂CH₂CH₂CH₃), 3-methyl-2-pentyl (—CH(CH₃)CH(CH₃)CH₂CH₃),4-methyl-2-pentyl (—CH(CH₃)CH₂CH(CH₃)₂), 3-methyl-3-pentyl(—C(CH₃)(CH₂CH₃)₂), 2-methyl-3-pentyl (—CH(CH₂CH₃)CH(CH₃)₂),2,3-dimethyl-2-butyl (—C(CH₃)₂CH(CH₃)₂), and 3,3-dimethyl-2-butyl(—CH(CH₃)C(CH₃)₃.

[0028] “Aryl” means a monovalent aromatic hydrocarbon radical of 6-20carbon atoms derived by the removal of one hydrogen atom from a singlecarbon atom of a parent aromatic ring system. Typical aryl groupsinclude, but are not limited to, radicals derived from benzene,substituted benzene, naphthalene, anthracene, biphenyl, and the like.

[0029] “Arylalkyl” refers to an acyclic alkyl radical in which one ofthe hydrogen atoms bonded to a carbon atom, typically a terminal or sp³carbon atom, is replaced with an aryl radical. Typical arylalkyl groupsinclude, but are not limited to, benzyl, 2-phenylethan-1-yl,2-phenylethen-1-yl, naphthylmethyl, 2-naphthylethan-1-yl,2-naphthylethen-1-yl, naphthobenzyl, 2-naphthophenylethan-1-yl and thelike. The arylalkyl group 6 to 20 carbon atoms e.g., the alkyl moiety,including alkanyl, alkenyl or alkynyl groups, of the arylalkyl group is1 to 6 carbon atoms and the aryl moiety is 5 to 14 carbon atoms.

[0030] “Substituted alkyl”, “substituted aryl”, and “substitutedarylalkyl” mean alkyl, aryl, and arylalkyl respectively, in which one ormore hydrogen atoms are each independently replaced with a substituent.Typical substituents include, but are not limited to, —X, —R, —O—, —OR,—SR, —S—, —NR₂, —NR₃, =NR, —CX₃, —CN, —OCN, —SCN, —N═C═O, —NCS, —NO,—NO₂, =N₂, —N₃, NC(═O)R, —C(═O)R, —C(═O)NRR—S(═O)₂O⁻, —S(═O)₂OH,—S(═O)₂R, —OS(═O)₂OR, —S(═O)₂NR, —S(═O)R, —OP(═O)O₂RR, —P(═O)O₂RR—P(═O)(O⁻)₂, —P(═O)(OH)₂, —C(═O)R, —C(═O)X, —C(S)R, —C(O)OR, —C(O)O⁻,—C(S)OR, —C(O)SR, —C(S)SR, —C(O)NRR, —C(S)NRR, —C(NR)NRR, where each Xis independently a halogen: F, Cl, Br, or I; and each R is independently—H, alkyl, aryl, heterocycle, or prodrug moiety.

[0031] “Heteroaryl” and “Heterocycle” refer to a ring system in whichone or more ring atoms is a heteroatom, e.g. nitrogen, oxygen, andsulfur. Heterocycles are described in: Katritzky, Alan R., Rees, C. W.,and Scriven, E. Comprehensive Heterocyclic Chemistry (1996) PergamonPress; Paquette, Leo A.; Principles of Modern Heterocyclic Chemistry W.A. Benjamin, New York, (1968), particularly Chapters 1, 3, 4, 6, 7, and9; “The Chemistry of Heterocyclic Compounds, A series of Monographs”(John Wiley & Sons, New York, 1950 to present), in particular Volumes13, 14, 16, 19, and 28. Exemplary heterocycles include but are notlimited to substituents, i.e. radicals, derived from pyrrole, indole,furan, benzofuran, thiophene, benzothiophene, 2-pyridyl, 3-pyridyl,4-pyridyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 2-imidazole, 4-imidazole,3-pyrazole, 4-pyrazole, pyridazine, pyrimidine, pyrazine, purine,cinnoline, pthalazine, quinazoline, quinoxaline, 3-(1,2,4-N)-triazolyl,5-(1,2,4-N)-triazolyl, 5-tetrazolyl, 4-(1-0,3-N)-oxazole,5-(1-0,3-N)-oxazole, 4-(1-S, 3-N)-thiazole, 5-(1-S, 3-N)-thiazole,2-benzoxazole, 2-benzothiazole, 4-(1,2,3-N)-benzotriazole, andbenzimidazole.

[0032] Stereochemical definitions and conventions used herein generallyfollow S. P. Parker, Ed., McGraw-Hill Dictionary of Chemical Terms(1984) McGraw-Hill Book Company, New York; and Eliel, E. and Wilen, S.,Stereochemistry of Organic Compounds (1994) John Wiley & Sons, Inc., NewYork. Many organic compounds exist in optically active forms, i.e., theyhave the ability to rotate the plane of plane-polarized light. Indescribing an optically active compound, the prefixes D and L or R and Sare used to denote the absolute configuration of the molecule about itschiral center(s). The prefixes R and S, d and l or (+) and (−) areemployed to designate the sign of rotation of plane-polarized light bythe compound, with (−) or 1 or S meaning that the compound islevorotatory. A compound prefixed with (+) or d or R is dextrorotatory.For a given chemical structure, these compounds, called stereoisomers,are identical except that they are mirror images of one another. Aspecific stereoisomer is also referred to as an enantiomer, and amixture of such isomers is often called an enantiomeric mixture. A 50:50mixture of enantiomers is referred to as a racemic mixture or aracemate. The terms “racemic mixture” and “racemate” refer to anequimolar mixture of two enantiomeric species, devoid of opticalactivity.

[0033] The term “chiral” refers to molecules which have the property ofnon-superimposability of the mirror image partner, while the term“achiral” refers to molecules which are superimposable on their mirrorimage partner.

[0034] The term “stereoisomers” refers to compounds which have identicalchemical constitution, but differ with regard to the arrangement of theatoms or groups in space.

[0035] “Diastereomer” refers to a stereoisomer with two or more centersof chirality and whose molecules are not mirror images of one another.Diastereomers have different physical properties, e.g. melting points,boiling points, spectral properties, and reactivities. Mixtures ofdiastereomers may separate under high resolution analytical proceduressuch as electrophoresis and chromatography.

[0036] “Enantiomers” refer to two stereoisomers of a compound which arenon-superimposable mirror images of one another.

[0037] Active Ingredients of the Combinations

[0038] The present invention provides novel combinations of two or moreactive ingredients being employed together. In some embodiments, asynergistic antiviral effect is achieved. In other embodiments, achemically stable combination is obtained. The combinations include atleast one active ingredient selected from (1) GS-7340 andphysiologically functional derivatives, and at least one activeingredient selected from (2) emtricitabine and physiologicallyfunctional derivatives. The term “synergistic antiviral effect” is usedherein to denote an antiviral effect which is greater than the predictedpurely additive effects of the individual components (a) and (b) of thecombination.

[0039] GS-7340 is an antiviral prodrug known as:9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine,and has the structure:

[0040] CAS Registry Numbers for GS-7340 include: 379270-37-8 and forGS-7340 fumarate include: 379270-38-9.

[0041] The prodrug GS-7340 is the subject of commonly owned, pendingapplication, U.S. Ser. No. 09/909,560, filed Jul. 20, 2001 and Becker etal WO 02/08241. GS-7340 is an isopropyl alanyl phosphonamidate, phenylester prodrug of tenofovir (PMPA). In vivo and in vitro characterizationshows that selective intracellular activation of GS 7340 leads topreferential distribution in lymphatic tissues (Lee W, He G, Mulato A,Delaney W, Eisenberg E, Cihlar T, Xiong S, Miller M, Gill S, Shibata R,Gibbs C Internatiional Conference on Retroviruses and OpportunisticInfections 2002, 9th Conf:February 24-28, Abs 384-T; “Evaluation ofCidofovir, Adefovir, Tenofovir and Related Phosphonate Analogs forInhibition of Orthopoxvirus Replication.” Keith K A, Hitchcock M J M,Lee W A, Holy A, Kern E R (2002) Antiviral Research, 53:3, Abs 95;“Structure and activity relationship for tenofovir amidates, novelintracellular prodrugs for tenofovir” He G X, Eisenberg E J, Cihlar T,Chapman H, Lee W A Antiviral Research 2001, 50:1, Abs 123)

[0042] Preclinical data on tenofovir prodrugs were presented at the 15thICAR meeting in Prague, Czech Republic. It was demonstrated that GS-7340is active against both cowpox and vaccinia viruses at concentrations of20 to 100 μM. GS-7340 is 1000 times more effective than tenofoviragainst HIV in culture. GS-7340 has an S-configuration at thephosphorus. This S-configuration diastereomer is 10-fold more effectivethan the diastereomer with the R-configuration (Nucleosides, Nucleotidesand Their Biological Applications—XIV International Roundtable (PartII), San Francisco, Calif., USA). The large-scale separation of GS-7340diastereomers and enantiomers has been achieved (“Practical synthesis,separation, and stereochemical assignment of the PMPA prodrug GS-7340”Chapman et al (2001) Nucleosides, Nucleotides & Nucleic Acids,20(4-7):621-628.

[0043] In vitro data showed that GS-7340 was effective against HIV andHBV in a variety of cell types. In vivo studies in dogs and rhesusmonkeys revealed that the compound is orally bioavailable (20%), stablein plasma and selectively hydrolyzed inside lymphatic tissue. In vitro,the most potent compounds displayed an EC50 value of 0.0008 μM againstHIV, and a half-life of 103 min in plasma. The prodrugs havedemonstrated oral bioavailability, stability and ability to rapidlyconvert to tenofovir inside lymphatic cells. GS-7340 is 100-fold moreeffective than tenofovir against HIV in culture, and the diastereomerwith an S-configuration at the P group is 10-fold more effective thanthat with an R-configuration. GS-7340 is in phase I/II trials for thepotential treatment of HIV and other viral infections.

[0044] The term “GS-7340” includes all combinations of stereochemistryat the three designated centers as well as all diasteromeric and racemicmixtures. Examples include R,R,R; R,R,S; R,S,R; S,R,R; R,S.S; S,R.S;S,S,R; and S,S,S compounds and their racemic, enantiomerically enrichedand partially racemic mixtures.

[0045] PMPA (U.S. Pat. Nos. 4,808,716, 5,733,788, 6057305) has thestructure:

[0046] The chemical names of PMPA include:(R)-9-(2-phosphonylmethoxypropyl)adenine; and phosphonic acid,[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]. The CASRegistry number is 147127-20-6.

[0047] Physiologically functional derivatives of GS-7340 includephosphonamidate PMEA (adefovir,9-((R)-2-(phosphonomethoxy)ethyl)adenine) and PMPA compounds. Exemplarycombinations include a phosphonamidate PMEA or PMPA compound incombination with emtricitabine or a physiologically functionalderivative. Phosphonamidate PMEA and PMPA compounds have the structures:

[0048] PMEA (R⁵=H) and PMPA (R⁵=CH₃). R⁶ and R⁸ are independentlyselected from H, C₁-C₆ alkyl, C₁-C₆ substituted alkyl, C₆-C₂₀ aryl,C₆-C₂₀ substituted aryl, C₆-C₂₀ arylalkyl, C₆-C₂₀ substituted arylalkyl.R⁷ is the side chain of any naturally-occurring or pharmaceuticallyacceptable amino acid and which, if the side chain comprises carboxyl,the carboxyl group is optionally esterified with an alkyl or aryl group.For example, R⁷ may be H, CH₃ or CH(CH₃)₂. R¹¹ is amino, alkylamino,oxo, or dialkylamino. R¹² is amino or H. Exemplary embodiments includewhere R is methyl, R⁶ is phenyl, and R⁸ is methyl, ethyl, or isopropyl.

[0049] Phosphonamidate PMEA and PMPA compounds may be prepared from thecorresponding dialkyl phosphonates which may be prepared according tothe methods of: Quast et al (1974) Synthesis 490; Stowell et al (1990)Tetrahedron Lett. 3261; U.S. Pat. No. 5,663,159.

[0050] The phosphonamidate PMEA and PMPA compound may beenantiomerically-enriched or purified (single stereoisomer) where thecarbon atom bearing R⁵ may be the R or S enantiomer when R⁵ is not H.The phosphonamidate PMEA and PMPA compound may be a racemate, i.e. amixture of R and S stereoisomers. The invention includes allenantiomers, diastereomers, racemates, and enriched stereoisomermixtures of phosphonamidate PMEA and PMPA compounds.

[0051] Emtricitabine ((−)-cis-FTC, Emtriva™), a single enantiomer ofFTC, is a potent nucleoside reverse transcriptase inhibitor approved forthe treatment of HIV (U.S. Pat. Nos. 5,047,407, 5,179,104, 5,204,466,5,210,085, 5,486,520, 5,538,975, 5,587,480, 5,618,820, 5,763,606,5,814,639, 5,914,331, 6,114,343, 6,180,639, 6,215,004; WO 02/070518).The single enantiomer emtricitabine has the structure:

[0052] The chemical names for emtricitabine include: (−)-cis-FTC;β-L-hydroxymethyl-5-(5-fluorocytosin-1-yl)-1,3-oxathiolane;(2R,5S)-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine; and4-amino-5-fluoro-1-(2-hydroxymethyl-[1,3]-(2R,5S)-oxathiolan-5-yl)-1H-pyrimidin-2-one.The CAS Registry numbers include: 143491-57-0; 143491-54-7. It should benoted that FTC contains two chiral centers, at the 2 and 5 positions ofthe oxathiolane ring, and therefore can exist in the form of two pairsof optical isomers (i.e. enantiomers) and diastereomeric and racemicmixtures thereof. Thus, FTC may be either a cis or a trans isomer ormixtures thereof. Mixtures of cis and trans isomers are diastereomerswith different physical properties. Each cis and trans isomer can existas one of two enantiomers or mixtures thereof including racemicmixtures. The invention includes all enantiomers, diastereomers,racemates, and enriched stereoisomer mixtures of emtricitabine, andphysiologically functional derivatives thereof. For example, theinvention includes physiological functional derivatives such as the 1:1racemic mixture of the enantiomers (2R, 5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine) and its mirror image (2S, 5R,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one,or mixtures of the two enantiomers in any relative amount. The inventionalso includes mixtures of cis and trans forms of FTC.

[0053] It will be appreciated that GS-7340 and emtricitabine may existin keto or enol tautomeric forms and the use of any tautomeric form iswithin the scope of this invention. GS-7340 and emtricitabine willnormally be utilized in the combinations of the invention substantiallyfree of the corresponding enantiomer, that is to say no more than about5% w/w of the corresponding enantiomer will be present.

[0054] Physiologically functional derivatives of emtricitabine include1,3 oxathiolane nucleosides having the structure:

[0055] In the 1,3 oxathiolane nucleoside structure above, B is anucleobase including any nitrogen-containing heterocyclic moiety capableof forming Watson-Crick hydrogen bonds in pairing with a complementarynucleobase or nucleobase analog, e.g. a purine, a 7-deazapurine, or apyrimidine. Examples of B include the naturally occurring nucleobases:adenine, guanine, cytosine, uracil, thymine, and minor constituents andanalogs of the naturally occurring nucleobases, e.g. 7-deazaadenine,7-deazaguanine, 7-deaza-8-azaguanine, 7-deaza-8-azaadenine, inosine,nebularine, nitropyrrole, nitroindole, 2-aminopurine,2-amino-6-chloropurine, 2,6-diaminopurine, hypoxanthine, pseudouridine,5-fluorocytosine, 5-chlorocytosine, 5-bromocytosine, 5-iodocytosine,5-alkylcytosine, e.g. 5-methylcytosine, pseudocytosine,pseudoisocytosine, 5-propynylcytosine, isocytosine, isoguanine,7-deazaguanine, 2-thiopyrimidine, 6-thioguanine, 4-thiothymine,4-thiouracil, 06-methylguanine, N6-methyladenine, 04-methylthymine,5,6-dihydrothymine, 5,6-dihydrouracil, 4-methylindole,pyrazolo[3,4-D]pyrimidines (U.S. Pat. Nos. 6,143,877 and 6,127,121; WO01/38584), and ethenoadenine (Fasman (1989) in Practical Handbook ofBiochemistry and Molecular Biology, pp. 385-394, CRC Press, Boca Raton,Fl).

[0056] Nucleobases B may be attached in the configurations ofnaturally-occurring nucleic acids to the 1,3 oxathiolane moiety througha covalent bond between the N-9 of purines, e.g. adenin-9-yl andguanin-9-yl, or N-1 of pyrimidines, e.g. thymin-1-yl and cytosin-1-yl(Blackburn, G. and Gait, M. Eds. “DNA and RNA structure” in NucleicAcids in Chemistry and Biology, 2^(nd) Edition, (1996) Oxford UniversityPress, pp. 15-81).

[0057] Also in the 1,3 oxathiolane nucleoside structure above, R is H,C₁-C₁₈ alkyl, C₂l-C₁₈ substituted alkyl, C₂-C₁₈ alkenyl, C₂-C₁₈substituted alkenyl, C₂-C₁₈ alkynyl, C₂-C₁₈ substituted alkynyl, C₆-C₂₀aryl, C₆-C₂₀ substituted aryl, C₂-C₂₀ heterocycle, C₂-C₂₀ substitutedheterocycle, phosphonate, phosphophosphonate, diphosphophosphonate,phosphate, diphosphate, triphosphate, polyethyleneoxy, or a prodrugmoiety

[0058] Physiologically functional derivatives of emtricitabine alsoinclude 3TC (lamivudine, Epivir®), a reverse transcriptase inhibitorapproved in the United States for the treatment of HIV-1 infection incombination with AZT (Zidovudine) as Combivir® (GlaxoSmithKline). U.S.Pat. Nos. 5,859,021; 5,905,082; 6,177,435; 5,627,186; 6,417,191. 3TC(U.S. Pat. Nos. 5,587,480, 5,696,254, 5,618,820, 5,756,706, 5,744,596,568,164, 5,466,806, 5,151,426) has the structure:

[0059] For example and for some therapeutic uses, 3TC may be aphysiologically functional derivative of emtricitabine in combinationwith GS-7340 or a physiologically functional derivative of GS-7340.

[0060] Prodrugs

[0061] The invention includes all prodrugs of GS-7340 and emtricitabine.Whereas GS-7340 is a prodrug form of a PMPA compound, GS-7340 may bearadditional prodrug moieties which confer advantageous properties. Alarge number of structurally-diverse prodrugs have been described forphosphonic acids (Freeman and Ross in Progress in Medicinal Chemistry34: 112-147 (1997). A commonly used prodrug class is the acyloxyalkylester, which was first used as a prodrug strategy for carboxylic acidsand then applied to phosphates and phosphonates by Farquhar et al (1983)J. Pharm. Sci. 72: 324; also U.S. Pat. Nos. 4,816,570, 4,968,788,5,663,159 and 5,792,756. Subsequently, the acyloxyalkyl ester was usedto deliver phosphonic acids across cell membranes and to enhance oralbioavailability. A close variant of the acyloxyalkyl ester strategy, thealkoxycarbonyloxyalkyl ester, may also enhance oral bioavailability as aprodrug moiety in the compounds of the combinations of the invention.Aryl esters of phosphorus groups, especially phenyl esters, are reportedto enhance oral bioavailability (DeLambert et al (1994) J. Med. Chem.37: 498). Phenyl esters containing a carboxylic ester ortho to thephosphate have also been described (Khamnei and Torrence, (1996) J. Med.Chem. 39:4109-4115). Benzyl esters are reported to generate the parentphosphonic acid. In some cases, substituents at the ortho- orpara-position may accelerate the hydrolysis. Benzyl analogs with anacylated phenol or an alkylated phenol may generate the phenoliccompound through the action of enzymes, e.g. esterases, oxidases, etc.,which in turn undergoes cleavage at the benzylic C—O bond to generatethe phosphoric acid and the quinone methide intermediate. Examples ofthis class of prodrugs are described by Mitchell et al (1992) J. Chem.Soc. Perkin Trans. I 2345; Brook et al WO 91/19721. Still other benzylicprodrugs have been described containing a carboxylic ester-containinggroup attached to the benzylic methylene (Glazier et al WO 91/19721).Thio-containing prodrugs are reported to be useful for the intracellulardelivery of phosphonate drugs. These proesters contain an ethylthiogroup in which the thiol group is either esterified with an acyl groupor combined with another thiol group to form a disulfide.Deesterification or reduction of the disulfide generates the free thiointermediate which subsequently breaks down to the phosphoric acid andepisulfide (Puech et al (1993) Antiviral Res., 22: 155-174; Benzaria etal (1996) J. Med. Chem. 39: 4958). Cyclic phosphonate esters have alsobeen described as prodrugs of phosphorus-containing compounds.

[0062] Prodrug esters in accordance with the invention are independentlyselected from the following groups: (1) mono-, di-, and tri-phosphateesters of GS-7340 or emtricitabine or any other compound which uponadministration to a human subject is capable of providing (directly orindirectly) said mono-, di, or triphosphate ester; (2) carboxylic acidesters (3) sulfonate esters, such as alkyl- or aralkylsulfonyl- (forexample, methanesulfonyl); (4) amino acid esters (for example, alanine,L-valyl or L-isoleucyl); (5) phosphonate; and (6) phosphonamidateesters.

[0063] Ester groups (1)-(6) may be substituted with; straight orbranched chain C₁-C₁₈ alkyl (for example, methyl, n-propyl, t-butyl, orn-butyl); C₃-C₁₂ cycloalkyl; alkoxyalkyl (for example, methoxymethyl);arylalkyl (for example, benzyl); aryloxyalkyl (for example,phenoxymethyl); C₅-C₂₀ aryl (for example, phenyl optionally substitutedby, for example, halogen, C₁-C₄ alkyl, C₁-C₄ alkoxy, or amino;acyloxymethyl esters —CH₂C(═O)R⁹ (e.g. POM) or acyloxymethyl carbonates—CH₂C(═O)OR⁹ (e.g. POC) where R⁹ is C₁-C₆ alkyl, C₁-C₆ substitutedalkyl, C₆-C₂₀ aryl or C₆-C₂₀ substituted aryl. For example, ester groupsmay be pivaloyloxymethoxy, POM, —CH₂C(═O)C(CH₃)₃; —CH₂C(═O)OC(CH₃)₃; orPOC, —CH₂C(═O)OCH(CH₃)₂.

[0064] An exemplary aryl moiety present in such esters comprises aphenyl or substituted phenyl group. Many phosphate prodrug moieties aredescribed in U.S. Pat. No. 6,312,662; Jones et al (1995) AntiviralResearch 27:1-17; Kucera et al (1990) AIDS Res. Hum. Retro Viruses6:491-501; Piantadosi et al (1991) J. Med. Chem. 34:1408-14; Hostelleret al (1992) Antimicrob. Agents Chemother. 36:2025-29; Hostetler et al(1990) J. Biol. Chem. 265:611127; and Siddiqui et al (1999) J. Med.Chem. 42:4122-28.

[0065] Pharmaceutically acceptable prodrugs refer to a compound that ismetabolized in the host, for example hydrolyzed or oxidized, by eitherenzymatic action or by general acid or base solvolysis, to form anactive ingredient. Typical examples of prodrugs of the activeingredients of the combinations of the invention have biologicallylabile protecting groups on a functional moiety of the active compound.Prodrugs include compounds that can be oxidized, reduced, aminated,deaminated, esterified, deesterified, alkylated, dealkylated, acylated,deacylated, phosphorylated, dephosphorylated, or other functional groupchange or conversion involving forming or breaking chemical bonds on theprodrug.

[0066] Chemical Stability of a Pharmaceutical Formulation

[0067] The chemical stability of the active ingredients in apharmaceutical formulation is of concern to minimize the generation ofimpurities and ensure adequate shelf-life. The active ingredients,GS-7340 and emtricitabine, in the pharmaceutical formulations of theinvention have relatively low pKa values, indicative of the potential tocause acidic hydrolysis of the active ingredients. Emtricitabine, with apKa of 2.65 (Emtriva™ Product Insert, Gilead Sciences, Inc. 2003,available at gilead.com) is subject to hydrolytic deamination of the5-fluoro cytosine nucleobase to form the 5-fluoro uridine nucleobase.Tenofovir, with a pKa of 3.8 (Yuan L. et al “Degradation Kinetics ofOxycarbonyloxymethyl Prodrugs of Phosphonates in Solution”,Pharmaceutical Research (2001) Vol. 18, No. 2, 234-237), is subject alsoto hydrolytic deamination of the exocyclic amine of the adeninenucleobase, and to hydrolysis of one or both of the amidate and estergroups (U.S. Pat. No. 5,922,695). It is desirable to formulate atherapeutic combination of GS-7340 and emtricitabine, and thephysiological functional derivatives thereof, with a minimum ofimpurities and adequate stability.

[0068] The combinations of the present invention provide combinationpharmaceutical dosage forms which are chemically stable to aciddegradation of: (1) a first component (such as GS-7340, andphysiological functional derivatives; (2) a second component (such asemtricitabine, and physiological functional derivatives; and (3)optionally a third component having antiviral activity. The thirdcomponent includes anti-HIV agents and include: protease inhibitors(PI), nucleoside reverse transcriptase inhibitors (NRTI), non-nucleosidereverse transcriptase inhibitors (NNRTI), and integrase inhibitors.Exemplary third active ingredients to be administered in combinationwith first and second components are shown in Table A. First and secondcomponents are as defined in the above section entitled: ACTIVEINGREDIENTS OF THE COMBINATIONS.

[0069] Salts

[0070] Any reference to any of the above compounds also includes areference to a physiologically acceptable salt thereof. Examples ofphysiologically acceptable salts of GS-7340, emtricitabine and theirphysiologically acceptable derivatives include salts derived from anappropriate base, such as an alkali metal (for example, sodium), analkaline earth (for example, magnesium), ammonium and NX₄ ⁺ (wherein Xis C₁-C₄ alkyl). Physiologically acceptable salts of an hydrogen atom oran amino group include salts of organic carboxylic acids such as acetic,benzoic, lactic, fumaric, tartaric, maleic, malonic, malic, isethionic,lactobionic and succinic acids; organic sulfonic acids, such asmethanesulfonic, ethanesulfonic, benzenesulfonic and p-toluenesulfonicacids; and inorganic acids, such as hydrochloric, sulfuric, phosphoricand sulfamic acids. Physiologically acceptable salts of a compound of anhydroxy group include the anion of said compound in combination with asuitable cation such as Na⁺ and NX₄ ⁺ (wherein X is independentlyselected from H or a C₁-C₄ alkyl group).

[0071] For therapeutic use, salts of active ingredients of thecombinations of the invention will be physiologically acceptable, i.e.they will be salts derived from a physiologically acceptable acid orbase. However, salts of acids or bases which are not physiologicallyacceptable may also find use, for example, in the preparation orpurification of a physiologically acceptable compound. All salts,whether or not derived from a physiologically acceptable acid or base,are within the scope of the present invention.

[0072] Administration of the Formulations

[0073] While it is possible for the active ingredients of thecombination to be administered alone and separately as monotherapies, itis preferable to administer them as a pharmaceutical co-formulation. Atwo-part or three-part combination may be administered simultaneously orsequentially. When administered sequentially, the combination may beadministered in one, two, or three administrations.

[0074] Preferably, two-part or three-part combinations are administeredin a single pharmaceutical dosage form. More preferably, a two-partcombination is administered as a single oral dosage form and athree-part combination is administered as two identical oral dosageforms. Examples include a single tablet of GS-7340 and emtricitabine, ortwo tablets of GS-7340, emtricitabine, and efavirenz.

[0075] It will be appreciated that the compounds of the combination maybe administered: (1) simultaneously by combination of the compounds in aco-formulation or (2) by alternation, i.e. delivering the compoundsserially, sequentially, in parallel or simultaneously in separatepharmaceutical formulations. In alternation therapy, the delay inadministering the second, and optionally a third active ingredient,should not be such as to lose the benefit of a synergistic therapeuticeffect of the combination of the active ingredients. By either method ofadministration (1) or (2), ideally the combination should beadministered to achieve peak plasma concentrations of each of the activeingredients. A one pill once-per-day regimen by administration of acombination co-formulation may be feasible for some HIV-positivepatients. Effective peak plasma concentrations of the active ingredientsof the combination will be in the range of approximately 0.001 to 100μM. Optimal peak plasma concentrations may be achieved by a formulationand dosing regimen prescribed for a particular patient. It will also beunderstood that GS-7340 and emtricitabine, or the physiologicallyfunctional derivatives of either thereof, whether presentedsimultaneously or sequentially, may be administered individually, inmultiples, or in any combination thereof. In general, during alternationtherapy (2), an effective dosage of each compound is administeredserially, where in co-formulation therapy (1), effective dosages of twoor more compounds are administered together.

[0076] Formulation of the Combinations

[0077] When the individual components of the combination areadministered separately they are generally each presented as apharmaceutical formulation. Techniques and formulations generally arefound in Remington's Pharmaceutical Sciences (Mack Publishing Co.,Easton, Pa.). The references hereinafter to formulations refer unlessotherwise stated to formulations containing either the combination or acomponent compound thereof. It will be understood that theadministration of the combination of the invention by means of a singlepatient pack, or patient packs of each formulation, within a packageinsert diverting the patient to the correct use of the invention is adesirable additional feature of this invention. The invention alsoincludes a double pack comprising in association for separateadministration, formulations of GS-7340 and emtricitabine, or aphysiologically functional derivative of either or both thereof.

[0078] The combination therapies of the invention include: (1) acombination of GS-7340 and emtricitabine or (2) a combination containinga physiologically functional derivative of either or both thereof.

[0079] The combination may be formulated in a unit dosage formulationcomprising a fixed amount of each active pharmaceutical ingredient for aperiodic, e.g. daily, dose or subdose of the active ingredients.

[0080] Pharmaceutical formulations according to the present inventioncomprise a combination according to the invention together with one ormore pharmaceutically acceptable carriers or excipients and optionallyother therapeutic agents. Pharmaceutical formulations containing theactive ingredient may be in any form suitable for the intended method ofadministration. For example, tablets, troches, lozenges, aqueous or oilsuspensions, dispersible powders or granules, emulsions, hard or softcapsules, syrups or elixirs may be prepared for oral administration(Remington's Pharmaceutical Sciences (Mack Publishing Co., Easton, Pa.).Compositions intended for oral use may be prepared according to anymethod known to the art for the manufacture of pharmaceuticalcompositions and such compositions may contain one or more agentsincluding antioxidants, sweetening agents, flavoring agents, coloringagents and preserving agents, in order to provide a palatablepreparation. Tablets containing the active ingredient in admixture withnon-toxic pharmaceutically acceptable excipient which are suitable formanufacture of tablets are acceptable. These excipients may be, forexample, inert diluents, such as calcium or sodium carbonate, lactose,lactose monohydrate, croscarmellose sodium, povidone, calcium or sodiumphosphate; granulating and disintegrating agents, such as maize starch,or alginic acid; binding agents, such as cellulose, microcrystallinecellulose, starch, gelatin or acacia; and lubricating agents, such asmagnesium stearate, stearic acid or talc. Tablets may be uncoated or maybe coated by known techniques including microencapsulation to delaydisintegration and absorption in the gastrointestinal tract and therebyprovide a sustained action over a longer period. For example, a timedelay material such as glyceryl monostearate or glyceryl distearatealone or with a wax may be employed.

[0081] Formulations for oral use may be also presented as hard gelatincapsules where the active ingredient is mixed with an inert soliddiluent, for example pregelatinized starch, calcium phosphate or kaolin,or as soft gelatin capsules wherein the active ingredient is mixed withwater or an oil medium, such as peanut oil, liquid paraffin or oliveoil.

[0082] Aqueous suspensions of the invention contain the active materialsin admixture with excipients suitable for the manufacture of aqueoussuspensions. Such excipients include a suspending agent, such as sodiumcarboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose,sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia,and dispersing or wetting agents such as a naturally occurringphosphatide (e.g., lecithin), a condensation product of an alkyleneoxide with a fatty acid (e.g., polyoxyethylene stearate), a condensationproduct of ethylene oxide with a long chain aliphatic alcohol (e.g.,heptadecaethyleneoxycetanol), a condensation product of ethylene oxidewith a partial ester derived from a fatty acid and a hexitol anhydride(e.g., polyoxyethylene sorbitan monooleate). The aqueous suspension mayalso contain one or more preservatives such as ethyl or n-propylp-hydroxybenzoate, one or more coloring agents, one or more flavoringagents and one or more sweetening agents, such as sucrose, sucralose, orsaccharin.

[0083] Oil suspensions may be formulated by suspending the activeingredient in a vegetable oil, such as arachis oil, olive oil, sesameoil or coconut oil, or in a mineral oil such as liquid paraffin. Theoral suspensions may contain a thickening agent, such as beeswax, hardparaffin or cetyl alcohol. Sweetening agents, such as those set forthabove, and flavoring agents may be added to provide a palatable oralpreparation. These compositions may be preserved by the addition of anantioxidant such as ascorbic acid, BHT, etc.

[0084] Dispersible powders and granules of the invention suitable forpreparation of an aqueous suspension by the addition of water providethe active ingredient in admixture with a dispersing or wetting agent, asuspending agent, and one or more preservatives. Suitable dispersing orwetting agents and suspending agents are exemplified by those disclosedabove. Additional excipients, for example sweetening, flavoring andcoloring agents, may also be present.

[0085] The pharmaceutical compositions of the invention may also be inthe form of oil-in-water emulsions or liposome formulations. The oilyphase may be a vegetable oil, such as olive oil or arachis oil, amineral oil, such as liquid paraffin, or a mixture of these. Suitableemulsifying agents include naturally-occurring gums, such as gum acaciaand gum tragacanth, naturally occurring phosphatides, such as soybeanlecithin, esters or partial esters derived from fatty acids and hexitolanhydrides, such as sorbitan monooleate, and condensation products ofthese partial esters with ethylene oxide, such as polyoxyethylenesorbitan monooleate. The emulsion may also contain sweetening andflavoring agents. Syrups and elixirs may be formulated with sweeteningagents, such as glycerol, sorbitol or sucrose. Such formulations mayalso contain a demulcent, a preservative, a flavoring or a coloringagent.

[0086] The pharmaceutical compositions of the invention may be in theform of a sterile injectable preparation, such as a sterile injectableaqueous or oleaginous suspension. This suspension may be formulatedaccording to the known art using those suitable dispersing or wettingagents and suspending agents which have been mentioned above. Thesterile injectable preparation may also be a sterile injectable solutionor suspension in a non-toxic parenterally acceptable diluent or solvent,such as a solution in 1,3-butane-diol or prepared as a lyophilizedpowder. Among the acceptable vehicles and solvents that may be employedare water, Ringer's solution and isotonic sodium chloride solution. Inaddition, sterile fixed oils may conventionally be employed as a solventor suspending medium. For this purpose any bland fixed oil may beemployed including synthetic mono- or diglycerides. In addition, fattyacids such as oleic acid may likewise be used in the preparation ofinjectables.

[0087] The pharmaceutical compositions of the invention may be injectedparenterally, for example, intravenously, intraperitoneally,intrathecally, intraventricularly, intrastemally, intracranially,intramuscularly or subcutaneously, or they may be administered byinfusion techniques. They are best used in the form of a sterile aqueoussolution which may contain other substances, for example, enough saltsor glucose to make the solution isotonic with blood. The aqueoussolutions should be suitably buffered (preferably to a pH of from 3 to9), if necessary. The preparation of suitable parenteral formulationsunder sterile conditions is readily accomplished by standardpharmaceutical techniques well known to those skilled in the art.

[0088] The pharmaceutical compositions of the invention may also beadministered intranasally or by inhalation and are convenientlydelivered in the form of a dry powder inhaler or an aerosol spraypresentation from a pressurized container or a nebuliser with the use ofa suitable propellant, e.g. dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane, a hydrofluoroalkanesuch as 1,1,1,2-tetrafluoroethane (HFC 134a), carbon dioxide or othersuitable gas In the case of a pressurized aerosol, the dosage unit maybe determined by providing a valve to deliver a metered amount. Thepressurized container or nebuliser may contain a solution or suspensionof the composition, e.g. using a mixture of ethanol and the propellantas the solvent, which may additional contain a lubricant, e.g. sorbitantrioleate. Capsules and cartridges (made, for example, from gelatin) foruse in an inhaler or insufflator may be formulated to contain a powdermix of a compound of the formula (I) and a suitable powder base such aslactose or starch. Aerosol or dry powder formulations are preferablyarranged so that each metered dose or “puff” contains from 20 μg to 20mg of a composition for delivery to the patient. The overall daily dosewith an aerosol will be in the range of from 20 μg to 20 mg which may beadministered in a single dose or, more usually, in divided dosesthroughout the day.

[0089] The amount of active ingredient that may be combined with thecarrier material to produce a single dosage form will vary dependingupon the host treated and the particular mode of administration. Forexample, a time-release formulation intended for oral administration tohumans may contain approximately from about 1 to 1000 mg of activematerial compounded with an appropriate and convenient amount of carriermaterial which may vary from about 5 to about 95% of the totalcompositions (weight:weight). The pharmaceutical composition can beprepared to provide easily measurable amounts for administration. Forexample, an aqueous solution intended for intravenous infusion maycontain from about 3 to 500 μg of the active ingredient per milliliterof solution in order that infusion of a suitable volume at a rate ofabout 30 mL/hr can occur. As noted above, formulations of the presentinvention suitable for oral administration may be presented as discreteunits such as capsules, cachets or tablets each containing apredetermined amount of the active ingredient; as a powder or granules;as a solution or a suspension in an aqueous or non-aqueous liquid; or asan oil-in-water liquid emulsion or a water-in-oil liquid emulsion. Theactive ingredient may also be administered as a bolus, electuary orpaste.

[0090] The combinations of the invention may conveniently be presentedas a pharmaceutical formulation in a unitary dosage form. A convenientunitary dosage formulation contains the active ingredients in amounts offrom about 1 mg to 1 g each, for example, 100 mg to 300 mg. Thesynergistic effects of GS-7340 in combination with emtricitabine may berealized over a wide ratio, for example 1:50 to 50:1 (GS-7340:emtricitabine). In one embodiment, the ratio may range from about 1:10to 10:1. In another embodiment, the weight/weight ratio of GS-7340 toemtricitabine in a co-formulated combination dosage form, such as apill, tablet, caplet or capsule will be about 1, i.e. an approximatelyequal amount of GS-7340 and emtricitabine. In other exemplaryco-formulations, there may be more or less GS-7340 than emtricitabine.Conveniently each compound will be employed in the combination in anamount at which it exhibits antiviral activity when used alone. Forexample, 150 mg GS-7340 and 200 mg emtricitabine can be co-formulated ina ratio of 0.75:1 (GS-7340: emtricitabine). In one embodiment, eachcompound will be employed in the combination in an amount at which itexhibits antiviral activity when used alone. Exemplary Formulations A,B, C, D, E, and F (Examples) have ratios of 0.125:1 to 1.5:1(GS-7340:emtricitabine). Exemplary Formulations A, B, C, D, E, and F useamounts of GS-7340 and emtricitabine ranging from 25 mg to 200 mg. Otherratios and amounts of the compounds of said combinations arecontemplated within the scope of the invention.

[0091] A unitary dosage form may further comprise GS-7340 andemtricitabine, or physiologically functional derivatives of eitherthereof, and a pharmaceutically acceptable carrier.

[0092] It will be appreciated by those skilled in the art that theamount of active ingredients in the combinations of the inventionrequired for use in treatment will vary according to a variety offactors, including the nature of the condition being treated and the ageand condition of the patient, and will ultimately be at the discretionof the attending physician or health care practitioner. The factors tobe considered include the route of administration and nature of theformulation, the animal's body weight, age and general condition and thenature and severity of the disease to be treated. For example, in aPhase 1111 monotherapy study of emtricitabine, patients received dosesranging from 25 mg to 200 mg twice-a-day for two weeks. At each doseregimen greater or equal to 200 mg, a 98-percent (1.75 log10) or greaterviral suppression was observed. A once-a-day dose of 200 mg ofemtricitabine reduced the viral load by an average of 99 percent (1.92log10). Emtriva™ (emtricitabine) has been approved by the FDA for thetreatment of HIV as a 200 mg oral tablet.

[0093] It is also possible to combine any two of the active ingredientsin a unitary dosage form for simultaneous or sequential administrationwith a third active ingredient. The three-part combination may beadministered simultaneously or sequentially. When administeredsequentially, the combination may be administered in two or threeadministrations. Third active ingredients have anti-HIV activity andinclude protease inhibitors (PI), nucleoside reverse transcriptaseinhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors(NNRTI), and integrase inhibitors. Exemplary third active ingredients tobe administered in combination with GS-7340, emtricitabine, and theirphysiological functional derivatives are shown in Table A. TABLE A 5,6dihydro-5-azacytidine 5-aza 2′deoxycytidine 5-azacytidine5-yl-carbocyclic 2′-deoxyguanosine (BMS200,475) 9(arabinofuranosyl)guanine; 9-(2′ deoxyribofuranosyl)guanine 9-(2′-deoxy2′fluororibofuranosyl)-2,6-diaminopurine 9-(2′-deoxy2′fluororibofuranosyl)guanine 9-(2′-deoxyribofuranosyl)-2,6diaminopurine 9-(arabinofuranosyl)-2,6 diaminopurine Abacavir, Ziagen ®Acyclovir, ACV; 9-(2-hydroxyethoxylmethyl)guanine Adefovir dipivoxil,Hepsera ® amdoxivir, DAPD Amprenavir, Agenerase ® araA;9-β-D-arabinofuranosyladenine (Vidarabine) atazanivir sulfate(Reyataz ®) AZT; 3′-azido-2′,3′-dideoxythymdine, Zidovudine,(Retrovir ®) BHCG;(.+−.)-(1a,2b,3a)-9-[2,3-bis(hydroxymethyl)cyclobutyl]guanineBMS200,475; 5-yl-carbocyclic 2′-deoxyguanosine Buciclovir; (R)9-(3,4-dihydroxybutyl)guanine BvaraU;1-β-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (Sorivudine) CalanolideA Capravirine CDG; carbocyclic 2′-deoxyguanosine Cidofovir, HPMPC;(S)-9-(3-hydroxy- 2-phosphonylmethoxypropyl)cytosine Clevudine, L-FMAU;2′-Fluoro-5-methyl-β-L-arabino-furanosyluracil Combivir ®(lamivudine/zidovudine) Cytallene;[1-(4′-hydroxy-1′,2′-butadienyl)cytosine] d4C;3′-deoxy-2′,3′-didehydrocytidine DAPD; (−)-β-D-2,6-diaminopurinedioxolane ddA; 2′,3′-dideoxyadenosine ddAPR;2,6-diaminopurine-2′,3′-dideoxyriboside ddC; 2′,3′-dideoxycytidine(Zalcitabine) ddI; 2′,3′-dideoxyinosine, didanosine, (Videx ®, Videx ®EC) Delavirdine, Rescriptor ® Didanosine, ddI, Videx ®;2′,3′-dideoxyinosine DXG; dioxolane guanosineE-5-(2-bromovinyl)-2′-deoxyuridine Efavirenz, Sustiva ® Enfuvirtide,Fuzeon ® F-ara-A; fluoroarabinosyladenosine (Fludarabine) FDOC;(−)-β-D-5-fluoro-1-[2-(hydroxymethyl)-1,3-dioxolane]cytosine FEAU;2′-deoxy-2′-fluoro-1-β-D-arabinofuranosyl-5-ethyluracil FIAC;1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-5-iodocytosine FIAU;1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-5-iodouridine FLG;2′,3′-dideoxy-3′-fluoroguanosine FLT; 3′-deoxy-3′-fluorothymidineFludarabine; F-ara-A; fluoroarabinosyladenosine FMAU;2′-Fluoro-5-methyl-β-L-arabino-furanosyluracil FMdC Foscarnet;phosphonoformic acid, PFA FPMPA;9-(3-fluoro-2-phosphonylmethoxypropyl)adenine Gancyclovir, GCV;9-(1,3-dihydroxy-2-propoxymethyl)guanine GS-7340;9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]- phenoxyphosphinyl]methoxy]propyl]adenine HPMPA;(S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine HPMPC;(S)-9-(3-hydroxy-2- phosphonylmethoxypropyl)cytosine (Cidofovir)Hydroxyurea, Droxia ® Indinavir, Crixivan ® Kaletra ®(lopinavir/ritonavir) Lamivudine, 3TC, Epivir ™; (2R, 5S, cis)-4-amino- 1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one L-d4C;L-3′-deoxy-2′,3′-didehydrocytidine L-ddC; L-2′,3′-dideoxycytidineL-Fd4C; L-3′-deoxy-2′,3′-didehydro-5-fluorocytidine L-FddC;L-2′,3′-dideoxy-5-fluorocytidine Lopinavir Nelfinavir, Viracept ®Nevirapine, Viramune ® Oxetanocin A;9-(2-deoxy-2-hydroxymethyl-β-D-erythro- oxetanosyl)adenine Oxetanocin G;9-(2-deoxy-2-hydroxymethyl-β-D-erythro- oxetanosyl)guanine PenciclovirPMEDAP; 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine PMPA, tenofovir;(R)-9-(2-phosphonylmethoxypropyl)adenine PPA; phosphonoacetic acidRibavirin; 1-β-D-ribofuranosyl-1,2,4-triazole-3-carboxamide Ritonavir,Norvir ® Saquinavir, Invirase ®, Fortovase ® Sorivudine, BvaraU;1-β-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil Stavudine, d4T, Zerit ®;2′,3′-didehydro-3′-deoxythymidine Trifluorothymidine, TFT;Trifluorothymidine Trizivir ® (abacavir sulfate/lamivudine/zidovudine)Vidarabine, araA; 9-β-D-arabinofuranosyladenine Viread ®, tenofovirdisoproxil fumarate (DF), Bis POC PMPA, TDF; 2,4,6,8-Tetraoxa-5-phosphanonanedioic acid, 5-[[(1R)- 2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]-,  bis(1-methylethyl)ester, 5-oxide, (2E)-2-butenedioate (1:1) Zalcitabine, Hivid ®, ddC;2′,3′-dideoxycytidine Zidovudine, AZT, Retrovir ®;3′-azido-2′,3′-dideoxythymdine Zonavir; 5-propynyl-1-arabinosyluracil

[0094] Another aspect of the present invention is a three-partcombination comprising GS-7340, emtricitabine, and tenofovir. TenofovirDF (also known as Viread®, Tenofovir disoproxil fumarate, Tenofovirdisoproxil, Tenofovir, TDF, Bis-POC-PMPA (U.S. Pat. Nos. 5,935,946,5,922,695, 5,977,089, 6,043,230, 6,069,249) has the structure:

[0095] The chemical names for Tenofovir disoproxil (DF) include:[2-(6-amino-purin-9-yl)-1-methyl-ethoxymethyl]-phosphonic aciddiisopropoxycarbonyloxymethyl ester; and2,4,6,8-tetraoxa-5-phosphanonanedioic acid,5-[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]-,bis(1-methylethyl) ester, 5-oxide. The CAS Registry numbers include:201341-05-1; 202138-50-9; 206184-49-8. It should be noted that theethoxymethyl unit of tenofovir (PMPA) has a chiral center. The R(rectus, right handed configuration) enantiomer is shown. However, theinvention includes the S isomer, as well. The invention includes allenantiomers, diastereomers, racemates, and enriched stereoisomermixtures of tenofovir and physiologically functional derivativesthereof.

[0096] Tenofovir DF is a new nucleotide reverse transcriptase inhibitorrecently approved in the United States for the treatment of HIV-1infection in combination with other antiretroviral agents. Tenofovirdisoproxil fumarate or Viread® (Gilead Science, Inc.) is the fumaratesalt of tenofovir disoproxil. Viread® may be named as:2,4,6,8-Tetraoxa-5-phosphanonanedioic acid,5-[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]-,bis(1-methylethyl) ester, 5-oxide, (2E)-2-butenedioate (1:1). The CASRegistry number is 202138-50-9.

[0097] For example, a typical unitary dosage may contain 1 mg to 1000 mgof GS-7340, 1 mg to 1000 mg of emtricitabine, and 1 mg to 1000 mg of thethird active ingredient. A unitary dosage form may further compriseGS-7340, emtricitabine, the third active ingredient, or physiologicallyfunctional derivatives of any of the active ingredients thereof, and apharmaceutically acceptable carrier.

[0098] Combinations of the present invention enable patients greaterfreedom from multiple dosage medication regimens and ease the neededdiligence required in remembering and complying with complex dailydosing times and schedules. By combining GS-7340 and emtricitabine intoa single dosage form, the desired daily regimen may be presented in asingle dose or as two or more sub-doses per day. The combination ofco-formulated GS-7340 and emtricitabine may be administered as a singlepill, once per day.

[0099] A further aspect of the invention is a patient pack comprising atleast one active ingredient GS-7340, emtricitabine or a physiologicallyfunctional derivative of either of the combination and an informationpackage or product insert containing directions on the use of thecombination of the invention.

[0100] Segregation of active ingredients in pharmaceutical powders andgranulations is a widely recognized problem that can result ininconsistent dispersions of the active ingredients in final dosageforms. Some of the main factors contributing to segregation are particlesize, shape and density. Segregation is particularly troublesome whenattempting to formulate a single homogenous tablet containing multipleactive ingredients having different densities and different particlesizes. Glidants are substances that have traditionally been used toimprove the flow characteristics of granulations and powders by reducinginterparticulate friction. See Lieberman, Lachman, & Schwartz,Pharmaceutical Dosage Forms: Tablets, Volume 1, p. 177-178 (1989),incorporated herein by reference. Glidants are typically added topharmaceutical compositions immediately prior to tablet compression tofacilitate the flow of granular material into the die cavities of tabletpresses. Glidants include: colloidal silicon dioxide, asbestos freetalc, sodium aluminosilicate, calcium silicate, powdered cellulose,microcrystalline cellulose, corn starch, sodium benzoate, calciumcarbonate, magnesium carbonate, metallic stearates, calcium stearate,magnesium stearate, zinc stearate, stearowet C, starch, starch 1500,magnesium lauryl sulfate, and magnesium oxide. Exemplary TabletFormulation A has colloidal silicon dioxide (Examples). Glidants can beused to increase and aid blend composition homogeneity in formulationsof anti-HIV drugs (U.S. Pat. No. 6,113,920). The novel compositions ofthe present invention may contain glidants to effect and maintainhomogeneity of active ingredients during handling prior to tabletcompression.

[0101] The present invention provides pharmaceutical formulationscombining the active ingredients GS-7340 and emtricitabine, orphysiologically functional derivatives thereof, in a sufficientlyhomogenized form, and a method for using this pharmaceuticalformulation. An object of the present invention is to utilize glidantsto reduce the segregation of active ingredients in pharmaceuticalcompositions during pre-compression material handling. Another object ofthe present invention is to provide a pharmaceutical formulationcombining the active ingredients GS-7340 and emtricitabine, orphysiologically functional derivatives thereof, with a pharmaceuticallyacceptable glidant, resulting in a mixture characterized by apharmaceutically acceptable measure of homogeneity.

[0102] Formulations include those suitable for oral, rectal, nasal,topical (including transdermal, buccal and sublingual), vaginal orparenteral (including subcutaneous, intramuscular, intravenous andintradermal) administration. The formulations may conveniently bepresented in unit dosage form and may be prepared by any methods wellknown in the art of pharmacy. Such methods represent a further featureof the present invention and include the step of bringing intoassociation the active ingredients with the carrier which constitutesone or more accessory ingredients. In general, the formulations areprepared by uniformly and intimately bringing into association theactive ingredients with liquid carriers or finely divided solid carriersor both, and then if necessary shaping the product.

[0103] Formulations of the present invention suitable for oraladministration may be presented as discrete units such as capsules,caplets, cachets or tablets each containing a predetermined amount ofthe active ingredients; as a powder or granules; as a solution or asuspension in an aqueous or non-aqueous liquid; or as an oil-in-waterliquid emulsion or a water-in-oil liquid emulsion. The active ingredientmay also be presented as a bolus, electuary or paste.

[0104] A tablet may be made by compression or molding, optionally withone or more accessory ingredients. Compressed tablets may be prepared bycompressing in a suitable machine the active ingredients in afree-flowing form such as a powder or granules, optionally mixed with abinder (e.g. povidone, gelatin, hydroxypropyl methylcellulose),lubricant, inert diluent, preservative, disintegrant (e.g. sodium starchglycollate, cross-linked povidone, cross-linked sodium carboxymethylcellulose) surface-active or dispersing agent. Molded tablets may bemade by molding a mixture of the powdered compound moistened with aninert liquid diluent in a suitable machine. The tablets may optionallybe coated or scored and may be formulated so as to provide slow orcontrolled release of the active ingredients therein using, for example,cellulose ether derivatives (e.g., hydroxypropyl methylcellulose) ormethacrylate derivatives in varying proportions to provide the desiredrelease profile. Tablets may optionally be provided with an entericcoating, to provide release in parts of the gut other than the stomach.

[0105] Formulations suitable for topical administration in the mouthinclude lozenges comprising the active ingredients in a flavored base,usually sucrose and acacia or tragacanth; pastilles comprising theactive ingredient in an inert basis such as gelatin and glycerin, orsucrose and acacia; and mouthwashes comprising the active ingredient ina suitable liquid carrier. Formulations for rectal administration may bepresented as a suppository with a suitable base comprising, for example,cocoa butter or a salicylates. Topical administration may also be bymeans of a transdermal iontophoretic device.

[0106] Formulations suitable for vaginal administration may be presentedas pessaries, tampons, creams, gels, pastes, foams or spray formulationscontaining in addition to the active ingredient such carriers as areknown in the art to be appropriate.

[0107] Formulations suitable for penile administration for prophylacticor therapeutic use may be presented in condoms, creams, gels, pastes,foams or spray formulations containing in addition to the activeingredient such carriers as are known in the art to be appropriate.

[0108] Pharmaceutical formulations suitable for rectal administrationwherein the carrier is a solid are most preferably presented as unitdose suppositories. Suitable carriers include cocoa butter and othermaterials commonly used in the art. The suppositories may beconveniently formed by admixture of the active combination with thesoftened or melted carrier(s) followed by chilling and shaping inmoulds.

[0109] Formulations suitable for parenteral administration includeaqueous and nonaqueous isotonic sterile injection solutions which maycontain anti-oxidants, buffers, bacteriostats and solutes which renderthe formulation isotonic with the blood of the intended recipient; andaqueous and non-aqueous sterile suspensions which may include suspendingagents and thickening agents; and liposomes or other microparticulatesystems which are designed to target the compound to blood components orone or more organs. The formulations may be presented in unit-dose ormulti-dose sealed containers, for example, ampoules and vials, and maybe stored in a freeze-dried (lyophilized) condition requiring only theaddition of the sterile liquid carrier, for example water for injection,immediately prior to use. Extemporaneous injection solutions andsuspensions may be prepared from sterile powders, granules and tabletsof the kind previously described.

[0110] Exemplary unit dosage formulations are those containing a dailydose or daily subdose of the active ingredients, as hereinbeforerecited, or an appropriate fraction thereof. It should be understoodthat in addition to the ingredients particularly mentioned above theformulations of this invention may include other agents conventional inthe art having regard to the type of formulation in question, forexample, those suitable for oral administration may include such furtheragents as sweeteners, thickeners and flavoring agents.

[0111] The compounds of the combination of the present invention may beobtained in a conventional manner, known to those skilled in the art.Tenofovir disoproxil fumarate can be prepared, for example, as describedin U.S. Pat. No. 5,977,089. Methods for the preparation of FTC aredescribed in WO 92/14743, incorporated herein by reference.

[0112] Composition Use

[0113] Compositions of the present invention are administered to a humanor other mammal in a safe and effective amount as described herein.These safe and effective amounts will vary according to the type andsize of mammal being treated and the desired results of the treatment.Any of the various methods known by persons skilled in the art forpackaging tablets, caplets, or other solid dosage forms suitable fororal administration, that will not degrade the components of the presentinvention, are suitable for use in packaging. The combinations may bepackaged in glass and plastic bottles. Tablets, caplets, or other soliddosage forms suitable for oral administration may be packaged andcontained in various packaging materials optionally including adessicant, e.g. silica gel. Packaging may be in the form of unit doseblister packaging. For example, a package may contain one blister trayof GS-7340 and another blister tray of emtricitabine pills, tablets,caplets, or capsule. A patient would take one dose, e.g. a pill, fromone tray and one from the other. Alternatively, the package may containa blister tray of the co-formulated combination of GS-7340 andemtricitabine in a single pill, tablet, caplet or capsule. As in othercombinations and packaging thereof, the combinations of the inventioninclude physiological functional derivatives of GS-7340 andemtricitabine.

[0114] The packaging material may also have labeling and informationrelated to the pharmaceutical composition printed thereon. Additionally,an article of manufacture may contain a brochure, report, notice,pamphlet, or leaflet containing product information. This form ofpharmaceutical information is referred to in the pharmaceutical industryas a “package insert.” A package insert may be attached to or includedwith a pharmaceutical article of manufacture. The package insert and anyarticle of manufacture labeling provides information relating to thepharmaceutical composition. The information and labeling providesvarious forms of information utilized by health-care professionals andpatients, describing the composition, its dosage and various otherparameters required by regulatory agencies such as the United StatesFood and Drug Agencies.

[0115] Assays of the Combinations

[0116] The combinations of the inventions may be tested for in vitroactivity against HIV and sensitivity, and for cytotoxicity in laboratoryadapted cell lines, e.g. MT2 and in peripheral blood mononuclear cells(PBMC) according to standard assays developed for testing anti-HIVcompounds, such as WO 02/068058 and U.S. Pat. No. 6,475,491. Combinationassays may be performed at varying concentrations of the compounds ofthe combinations to determine EC₅₀ by serial dilutions.

EXAMPLES

[0117] The following examples further describe and demonstrateparticular embodiments within the scope of the present invention. Theexamples are given solely for illustration and are not to be construedas limitations as many variations are possible without departing fromspirit and scope of the Invention. The following examples are intendedfor illustration only and are not intended to limit the scope of theinvention in any way. “Active ingredient” denotes GS-7340,emtricitabine, or a physiologically functional derivative of eitherthereof.

[0118] Tablet Formulation

[0119] The following exemplary formulations A, B, C, D, E, and F areprepared by wet granulation of the ingredients with an aqueous solution,addition of extragranular components and then followed by addition ofmagnesium stearate and compression. mg/tablet Formulation A: GS-7340 150emtricitabine 200 Microcrystalline Cellulose 200 Lactose Monohydrate 325Sodium Starch Glycollate 60 Pregelatinized Starch 50 Colloidal silicondioxide 5 Magnesium Stearate 10 1000 Formulation B: GS-7340 150emtricitabine 200 Microcrystalline Cellulose 200 Lactose Monohydrate 330Croscarmellose Sodium 60 Pregelatinized Starch 50 Magnesium Stearate 101000 Formulation C: GS-7340 50 emtricitabine 200 MicrocrystallineCellulose 200 Lactose Monohydrate 330 Croscarmellose Sodium 60Pregelatinized Starch 50 Magnesium Stearate 10 900 Formulation D:GS-7340 25 emtricitabine 200 Microcrystalline Cellulose 200 LactoseMonohydrate 330 Croscarmellose Sodium 60 Pregelatinized Starch 50Magnesium Stearate 10 875 Formulation E: GS-7340 150 emtricitabine 100Microcrystalline Cellulose 200 Lactose Monohydrate 330 CroscarmelloseSodium 60 Pregelatinized Starch 50 Magnesium Stearate 10 900 FormulationF: GS-7340 100 emtricitabine 100 Microcrystalline Cellulose 200 LactoseMonohydrate 330 Croscarmellose Sodium 60 Pregelatinized Starch 50Magnesium Stearate 10 850

[0120] Formulation G (Controlled Release Formulation):

[0121] This formulation is prepared by wet granulation of theingredients with an aqueous solution, followed by the addition ofmagnesium stearate and compression. mg/tablet GS-7340 300 emtricitabine200 Hydroxypropyl Methylcellulose 112 Lactose B.P. 53 PregelatinizedStarch B.P. 28 Magnesium Stearate 7 total: 700

[0122] Drug release takes place over a period of about 6-8 hours and iscomplete after 12 hours.

[0123] Capsule Formulations

[0124] Formulation H:

[0125] A capsule formulation is prepared by admixing the ingredients andfilling into a two-part hard gelatin or hydroxypropyl methylcellulosecapsule. mg/capsule Active Ingredient 500 Microcrystalline Cellulose 143Sodium Starch Glycollate 25 Magnesium Stearate 2 total: 670

[0126] Formulation I (Controlled Release Capsule):

[0127] The following controlled release capsule formulation is preparedby extruding ingredients a, b, and c using an extruder, followed byspheronization of the extrudate and drying. The dried pellets are thencoated with release-controlling membrane (d) and filled into atwo-piece, hard gelatin or hydroxypropyl methylcellulose capsule.mg/capsule (a) Active Ingredient 500 (b) Microcrystalline Cellulose 125(c) Lactose B.P. 125 (d) Ethyl Cellulose 13 total: 763

[0128] Formulation J (Oral Suspension):

[0129] The active ingredients are admixed with the ingredients andfilling them as dry powder. Purified water is added and mixed wellbefore use. Active Ingredient  500 mg Confectioner's Sugar 2000 mgSimethicone  300 mg Methylparaben  30 mg Propylparaben  10 mg Flavor,Peach  500 mg Purified Water q.s. to  5.00 ml

[0130] Formulation K (Suppository):

[0131] One-fifth of the Witepsol H15 is melted in a steam-jacketed panat 45° C. maximum. The active ingredients are sifted through a 200micron sieve and added to the molten base with mixing, using a Silversonfitted with a cutting head, until a smooth dispersion is achieved.Maintaining the mixture at 45° C., the remaining Witepsol H15 is addedto the suspension and stirred to ensure a homogenous mix. The entiresuspension is passed through a 250 micron stainless steel screen and,with continuous stirring, is allowed to cool to 40° C. At a temperatureof 38° C. to 40° C., 2.02 g of the mixture is filled into suitable, 2 mLplastic molds. The suppositories are allowed to cool to roomtemperature. mg/Suppository Active Ingredient 500 Hard Fat, B.P.(Witepsol H15 - Dynamit 1770 Nobel) total 2270

[0132] A fixed dose combination tablet of GS-7340 and emtricitabine, ortheir physiologically functional derivatives, may be formulated using awet granulation/fluid-bed drying process using conventional methods.See: U.S. Pat. No. 5,935,946; L. Young (editor). Tableting SpecificationManual 5^(th) ed., American Pharmaceutical Association, Washington,D.C., (2001); L. Lachman, H. Lieberman (editors). Pharmaceutical DosageForms: Tablets (Vol 2), Marcel Dekker Inc., New York, 185-202 (1981); J.T. Fell and J. M. Newton, J. Pharm. Pharmacol. 20, 657-659 (1968); USPharmacopeia 24-National Formulary 19, “Tablet Friability”, Chapter<1216>, Page 2148 (2000).

[0133] All publications and patent applications cited herein areincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated to be incorporated by reference.

[0134] Although certain embodiments are described in detail above, thosehaving ordinary skill in the art will clearly understand that manymodifications are possible in the embodiments without departing from theteachings thereof. All such modifications are intended to be encompassedwithin the claims of the invention.

[0135] Embodiments of the Invention:

[0136] A. A pharmaceutical composition comprising an effective amount ofa compound of the formula:

[0137] wherein R⁵ is H or CH₃; R⁶ and R⁸ are independently selected fromH, C₁-C₆ alkyl, C₁-C₆ substituted alkyl, C₆-C₂₀ aryl, C₆-C₂₀ substitutedaryl, C₆-C₂₀ arylalkyl, and C₆-C₂₀ substituted arylalkyl; R⁷ is the sidechain of any naturally-occurring or pharmaceutically acceptable aminoacid and where if the side chain comprises carboxyl, the carboxyl groupis optionally esterified with an alkyl or aryl group; R¹¹ is amino,alkylamino, oxo, or dialkylamino; and R¹² is amino or H;

[0138] or a physiologically functional derivative thereof;

[0139] in combination with an effective amount of a compound of theformula

[0140] wherein B is selected from adenine, guanine, cytosine, uracil,thymine, 7-deazaadenine, 7-deazaguanine, 7-deaza-8-azaguanine,7-deaza-8-azaadenine, inosine, nebularine, nitropyrrole, nitroindole,2-aminopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, hypoxanthine,pseudouridine, 5-fluorocytosine, 5-chlorocytosine, 5-bromocytosine,5-iodocytosine, pseudocytosine, pseudoisocytosine, 5-propynylcytosine,isocytosine, isoguanine, 7-deazaguanine, 2-thiopyrimidine,6-thioguanine, 4-thiothymine, 4-thiouracil, O⁶-methylguanine,N⁶-methyladenine, O⁴-methylthymine, 5,6-dihydrothymine,5,6-dihydrouracil, 4-methylindole, and a pyrazolo[3,4-D]pyrimidine; and

[0141] R is selected from H, C₁-C₁₈ alkyl, C₁-C₁₈ substituted alkyl,C₂-C₁₈ alkenyl, C₂-C₁₈ substituted alkenyl, C₂-C₁₈ is alkynyl, C₂-C₁₈substituted alkynyl, C₆-C₂₀ aryl, C₆-C₂₀ substituted aryl, C₂-C₂₀heterocycle, C₂-C₂₀ substituted heterocycle, phosphonate,phosphophosphonate, diphosphophosphonate, phosphate, diphosphate,triphosphate, polyethyleneoxy or a physiologically functional derivativethereof; and

[0142] a pharmaceutically acceptable carrier.

[0143] B. A composition of embodiment A wherein, in formula 1, R⁷ is H,CH₃ or CH(CH₃)₂.

[0144] C. A composition of embodiment A wherein, in formula 1, R⁶ isphenyl.

[0145] D. A composition of embodiment A wherein, in formula 1, R⁸ isCH₃, CH₂CH₃, or CH(CH₃)₂.

[0146] E. A composition of embodiments A through D wherein, in formula2, B is cytosine or a 5-halocytosine and R is H.

[0147] F. A composition of embodiments A through E wherein, in formula2, B is 5-fluorocytosine and R is H.

[0148] G. A pharmaceutical formulation of embodiments A through Ffurther comprising a third active ingredient selected from the groupconsisting of a protease inhibitor, a nucleoside or nucleotide reversetranscriptase inhibitor, a non-nucleoside reverse transcriptaseinhibitor, and an integrase inhibitor.

[0149] H. A pharmaceutical formulation of embodiments A through G inunit dosage form.

[0150] I. A method for the treatment or prevention of the symptoms oreffects of an HIV infection in an infected animal which comprisesadministering to said animal a pharmaceutical composition of embodimentsA through G.

We claim:
 1. A method for the treatment or prevention of the symptoms oreffects of an HIV infection in an infected animal which comprisesadministering to said animal a therapeutically effective amount of acombination comprising9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) or a physiologically functional derivative thereof, and(2R,5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine) or a physiologically functional derivative thereof. 2.The method according to claim 1 wherein the combination comprisesGS-7340 and emtricitabine.
 3. The method according to claim 2 whereinthe combination comprises about 150 mg of GS-7340 and about 200 mg ofemtricitabine.
 4. The method according to claim 1 wherein GS-7340 or aphysiologically functional derivative thereof and emtricitabine or aphysiologically functional derivative thereof are present in a ratio ofabout 1:50 to about 50:1 by weight.
 5. The method according to claim 1wherein GS-7340 or a physiologically functional derivative thereof andemtricitabine or a physiologically functional derivative thereof arepresent in a ratio of about 1:10 to about 10:1 by weight.
 6. The methodaccording to claim 1 wherein GS-7340 or a physiologically functionalderivative thereof and emtricitabine or a physiologically functionalderivative thereof are each present in an amount from about 1 mg toabout 1000 mg per unit dosage form.
 7. The method according to claim 1wherein GS-7340 or a physiologically functional derivative thereof andemtricitabine or a physiologically functional derivative thereof areeach present in an amount from about 100 mg to about 300 mg per unitdosage form.
 8. A method according to claim 1 wherein GS-7340 is afumarate salt.
 9. A method for the treatment or prevention of thesymptoms or effects of an HIV infection in an infected animal whichcomprises administering to said animal a therapeutically effectiveamount of a combination comprising9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) or a physiologically functional derivative thereof, and acompound of the formula:

wherein B is selected from adenine, guanine, cytosine, uracil, thymine,7-deazaadenine, 7-deazaguanine, 7-deaza-8-azaguanine,7-deaza-8-azaadenine, inosine, nebularine, nitropyrrole, nitroindole,2-aminopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, hypoxanthine,pseudouridine, 5-fluorocytosine, 5-chlorocytosine, 5-bromocytosine,5-iodocytosine, pseudocytosine, pseudoisocytosine, 5-propynylcytosine,isocytosine, isoguanine, 7-deazaguanine, 2-thiopyrimidine,6-thioguanine, 4-thiothymine, 4-thiouracil, O⁶-methylguanine,N⁶-methyladenine, O⁴-methylthymine, 5,6-dihydrothymine,5,6-dihydrouracil, 4-methylindole, and a pyrazolo[3,4-D]pyrimidine; andR is selected from H, C₁-C₁₈ alkyl, C₁-C₁₈ substituted alkyl, C₂-C₁₈alkenyl, C₂-C₁₈ substituted alkenyl, C₂-C₁₈ alkynyl, C₂-C₁₈ substitutedalkynyl, C₆-C₂₀ aryl, C₆-C₂₀ substituted aryl, C₂-C₂₀ heterocycle,C₂-C₂₀ substituted heterocycle, phosphonate, phosphophosphonate,diphosphophosphonate, phosphate, diphosphate, triphosphate,polyethyleneoxy, and a prodrug moiety.
 10. The method according to claim9 wherein the combination comprises a physiologically functionalderivative of emtricitabine which is (2R, 5S,cis)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(3TC).
 11. The method according to claim 1 wherein the combinationcomprises a physiologically functional derivative of emtricitabine whichis a racemic mixture of the enantiomers (2R, 5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-oneand (2S, 5R,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one.12. The method according to claim 1 wherein the combination comprises aphysiologically functional derivative of GS-7340 which has thestructure:

wherein R⁵ is H or CH₃; R⁶ and R⁸ are independently selected from H,C₁-C₆ alkyl, C₁-C₆ substituted alkyl, C₆-C₂₀ aryl, C₆-C₂₀ substitutedaryl, C₆-C₂₀ arylalkyl, and C₆-C₂₀ substituted arylalkyl; R⁷ is the sidechain of any naturally-occurring or pharmaceutically acceptable aminoacid and where if the side chain comprises carboxyl, the carboxyl groupis optionally esterified with an alkyl or aryl group; R¹¹ is amino,alkylamino, oxo, or dialkylamino; and R¹² is amino or H; or apharmaceutically acceptable salt or solvate thereof.
 13. The methodaccording to claim 12 wherein R⁷ is H, CH₃ or CH(CH₃)₂.
 14. The methodaccording to claim 12 wherein R⁶ is phenyl.
 15. The method according toclaim 12 wherein R⁸ is CH₃, CH₂CH₃, or CH(CH₃)₂.
 16. The methodaccording to claim 1 wherein GS-7340 or a physiologically functionalderivative thereof, and emtricitabine or a physiologically functionalderivative thereof are administered sequentially.
 17. The methodaccording to claim 1 wherein the combination is administered as a singlecombined formulation.
 18. The method according to claim 17 wherein thesingle combined formulation is administered once per day to an infectedhuman.
 19. The method according to claim 1 in which said animal is ahuman.
 20. The method according to claim 1 wherein the combinationfurther comprises a third active ingredient selected from a proteaseinhibitor (PI), a nucleoside reverse transcriptase inhibitor (NRTI), anon-nucleoside reverse transcriptase inhibitor (NNRTI), and an integraseinhibitor.
 21. The method according to claim 20 wherein the third activeingredient is tenofovir disoproxil fumarate.
 22. The method according toclaim 1 wherein the combination further comprises a pharmaceuticallyacceptable glidant selected from silicon dioxide, powdered cellulose,microcrystalline cellulose, a metallic stearate, sodium aluminosilicate,sodium benzoate, calcium carbonate, calcium silicate, corn starch,magnesium carbonate, asbestos free talc, stearowet C, starch, starch1500, magnesium lauryl sulfate, magnesium oxide, and combinationsthereof.
 23. The method according to claim 22 wherein the metallicstearate is selected from calcium stearate, magnesium stearate, zincstearate, and combinations thereof.
 24. A pharmaceutical formulationcomprising9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) or a physiologically functional derivative thereof and (2R,5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine) or a physiologically functional derivative thereof. 25.The pharmaceutical formulation according to claim 24 further comprisingone or more pharmaceutically acceptable carriers or excipients.
 26. Thepharmaceutical formulation according to claim 25 wherein thepharmaceutically acceptable carriers or excipients are selected frompregelatinized starch, croscarmellose sodium, povidone, lactosemonohydrate, microcrystalline cellulose, and magnesium stearate; andcombinations thereof.
 27. The pharmaceutical formulation according toclaim 24 wherein GS-7340 or a physiologically functional derivativethereof and emtricitabine or a physiologically functional derivativethereof are present in a ratio of 1:50 to 50:1 by weight.
 28. Thepharmaceutical formulation according to claim 24 wherein GS-7340 or aphysiologically functional derivative thereof and emtricitabine or aphysiologically functional derivative thereof are present in a ratio of1:10 to 10:1 by weight.
 29. The pharmaceutical formulation according toclaim 24 in unit dosage form.
 30. The pharmaceutical formulationaccording to claim 29 wherein GS-7340 or a physiologically functionalderivative thereof and emtricitabine or a physiologically functionalderivative thereof are each and individually present in an amount from100 mg to 1000 mg per unit dosage form.
 31. The pharmaceuticalformulation according to claim 24 comprising GS-7340 and emtricitabine.32. The pharmaceutical formulation according to claim 31 comprisingabout 150 mg of GS-7340 and about 200 mg of emtricitabine.
 33. Thepharmaceutical formulation according to claim 24 suitable for oraladministration.
 34. The pharmaceutical formulation according to claim 30in the form of a tablet or capsule.
 35. The pharmaceutical formulationaccording to claim 30 suitable for administration once per day to aninfected human.
 36. The pharmaceutical formulation according to claim 24comprising a physiologically functional derivative of emtricitabinewhich is (2R, 5S,cis)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(3TC).
 37. The pharmaceutical formulation according to claim 24comprising a physiologically functional derivative of GS-7340 which hasthe structure:

wherein R⁵ is H or CH₃; R⁶ and R⁸ are independently selected from H,C₁-C₆ alkyl, C₁-C₆ substituted alkyl, C₆-C₂₀ aryl, C₆-C₂₀ substitutedaryl, C₆-C₂₀ arylalkyl, and C₆-C₂₀ substituted arylalkyl; R⁷ is the sidechain of any naturally-occurring or pharmaceutically acceptable aminoacid and where if the side chain comprises carboxyl, the carboxyl groupis optionally esterified with an alkyl or aryl group; R¹¹ is amino,alkylamino, oxo, or dialkylamino; and R¹² is amino or H; or apharmaceutically acceptable salt or solvate thereof.
 38. Thepharmaceutical formulation according to claim 37 wherein R⁷ is H, CH₃ orCH(CH₃)₂.
 39. The pharmaceutical formulation according to claim 37wherein R⁶ is phenyl.
 40. The pharmaceutical formulation according toclaim 37 wherein R⁸ is CH₃, CH₂CH₃, or CH(CH₃)₂.
 41. A patient packcomprising at least one active ingredient selected from9-[R-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]-phenoxyphosphinyl]methoxy]propyl]adenine(GS-7340) and (2R,5S,cis)-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one(emtricitabine), and an information insert containing directions on theuse of GS-7340 and emtricitabine together in combination.
 42. Thepatient pack according to claim 41 comprising a co-formulated pill,tablet, caplet, or capsule of 100 to 1000 mg of GS-7340 and 100 to 1000mg of emtricitabine.
 43. The patient pack according to claim 41comprising a co-formulated pill, tablet, caplet, or capsule of 300 mg ofGS-7340 and 200 mg of emtricitabine.
 44. The patient pack according toclaim 41 comprising a separate pill, tablet, caplet, or capsule of 100to 1000 mg of GS-7340 and 100 to 1000 mg of emtricitabine.
 45. Thepatient pack according to claim 44 comprising a separate pill, tablet,caplet, or capsule of 150 mg of GS-7340 and 200 mg of emtricitabine. 46.A chemically stable combination of GS-7340 and emtricitabine.
 47. Thechemically stable combination of claim 46 wherein the combination is apharmaceutical dosage form.
 48. The chemically stable combination ofclaim 47 wherein the dosage form is oral.
 49. The chemically stablecombination of claims 46-48 which further comprises a third antiviralagent.
 50. The chemically stable combination of claim 49 where in thethird antiviral agent is an NNRTI or PI.
 51. The chemically stablecombination of claim 50 wherein the third antiviral agent is a PI. 52.The chemically stable combination of Clam 50 wherein the third antiviralagent is an NNRTI.
 53. The chemically stable combination of claim 49wherein the third antiviral agent is selected from Reyataz, Kaletra orSustiva.
 54. A chemically stable oral pharmaceutical dosage formcomprising GS-7340 and emtricitabine.
 55. A chemically stable oralpharmaceutical dosage form comprising GS-7340, emtricitabine andReyataz.
 56. A chemically stable oral pharmaceutical dosage formcomprising GS-7340, emtricitabine and Kaletra.
 57. A chemically stableoral pharmaceutical dosage form comprising GS-7340, emtricitabine andSustiva.